Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 4/21/2016

My newly built lanai is cinder block with a veneer of stucco. It had a bad smell which paint didn't change. Help!

The room is now 6 months old. Air dissipates but does not cure the smell.

Do you have the same question? Follow this Question

1 Answer


I am going to assume the problem is not the paint itself, and that this smell developed - was not there when the structure was first put up. If it was there initially, you may have gotten "rotten egg" cinder block - true cinder block (as opposed to concrete building block) which contains a high level of sulfer from the coal that was burned. (Cinder block has a large fraction of coal power plant flyash in it, regular concrete building block is basically concrete with a few additives to improve flow into the forms). If that is the case, there is basically no perfect solution, though sometimes an epoxy or polyurea paint can block it fairly well. Under current practice but not enshrined in code that I know of, "cinder block", as opposed to concrete block, should not be used in interior applications - only as exterior surfaces or for foundations that are not exposed to the "conditioned space" on the inside - like in basements or half-wall daylight basement foundations for instance.

You say "lanai', but then "room" after that. My guess is you violated the number one rule of a "lanai" or patio - you have to maintain basically unrestricted natural ventilation. A "lanai" (which basically means patio in Hawaiian) has a sun shade cover but is wide open on 3 sides (with house on fourth side) - either totally open or insect screened.

Far too many people (including builders and architects) ignore the fact, especially if it includes any sort of pool or water feature or planters in it, that as soon as you start enclosing it by putting in walls you start building humidity. This is rapidly aggravated by the fact the enclosure commonly is intentionally exposed to solar heating (i.e. except in hottest areas on sunny side of the house), so as the temperature inside rises the moisture from the soil and air goes into high moisture content in the air. As that air contacts the cold ground or concrete, and also as the room cools off in the evening, that high moisture sstarts condensing out on the colder surfaces - which depending on your outdoor temperatures at night, can be on the floor (especially if brick, stone, concrete, etc), on block or concrete lower walls, and eventually can even occur on glass, walls, and the underside of the cover if it gets cold enough outside. This is creating basically a greenhouse effect - good for plants, not so good for people and building materials. This moisture, especially if it soaks into porous flooring or wall materials, then keeps that area moist for much or even all the day - promoting mildew and mold growth.

This commonly is made worse by closing the room up at night (closing windows and such), trapping the high moisture level contained in the warm air inside the room so it condenses as the room cools at night rather than dissipating into nature and condensing or dropping out as fog or dew outside. Of course, this behavior sometimes tends to be worse in the fall and winter when it gets colder at night, but in some cases spring or summer are worse because the higher temperature promotes fungal and mold growth.

Commonly, humidistat controlled dehumidification and heating at night to keep it from getting so cold is a partial solution, in combination with eliminating in-room water sources like plants and ponds - though of course that heating is energy inefficient and not viable unless it is totally enclosed.

You need to air the room out well, then close it up tight and turn off any fan or ventilation to the room, then go around the room (may take a ladder for higher areas) and use your nose to sniff around for where the odor is coming from - usually but not always a cold floor or lower wall area or planters, sometimes hangings like curtains or drapes especially if touching the glass or metal frame. Very commonly organic material flooring (carpet, laminate, engineered or hardwood) over concrete slab without a vapor barrier.

Once you track down the source you can determine whether cleaning and chlorine bleach (being careful of damage to surfaces) will access and kill it or not. You may need a mold remediation contractor. Of course, you have to cure the humidity issue as well or it will just come back.

One thing - if you have a warranty on this that is still in effect, AND the construction was designed by the builder rather than an architect working directly for you, you may be able to claim warranty repair for "sick house" syndrome - basically inadequate ventilation designed in. If you had it designed yourself, then possible recourse against the architect's Errors and Omissions insurance. Of course, you have to show that the problem is a design flaw, not caused by something YOU are doing.

Answered 4 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy